Please help me to review my ielts essay

Unforgettable Memory
When I was small, I was always taught that lying is not good. But I, a great student in the eyes of my teachers and my friends once did that. It happened when I was in secondary school, which made me always feel ashamed whenever I remember. That morning, we had a lesson of mathematics. Because the week before I was called to check the old lesson and I scored 9 points so I was confident that I would not be checked again. With that in mind, I did not study and do the homework. When the school drum sounded, our teacher entered the classroom. As usual, she asked us if anyone had not done homework. I'm confident to answer her that I had done it. Unfortunately, she asked all the class to collect notebooks to check and get mark. At that time, I was both surprised and scared. If I did not give her my notebook, I would not have a point. But If I gave her mine, I could make sure she would discover that I had not done the homework. That was so shameful to a good student like me.
So, I decided to lie to the teacher: "I did my homework but my notebook was gone. I do not know who stole it”, and I tried to shed tears. Of course, the teacher and my classmates believed what I said. Some of my friends were suspected of having hidden my notebook. Then, the teacher asked all my class to look around our seats to see if anyone could see where my notebook was, but it was useless. As a result, I not only did not get bad mark but also received sympathy from everyone.
After school, when I returned home, I felt very regretful. I found myself cowardly. I told that story to my mother and she gave me some useful advices. The next morning, I went to school earlier than usual. I met and apologized to my teacher and my classmates. I imagined the teacher would punish me so badly, but she said softly: “You have known your mistake, which is very good. And from now then, you should not do that again. " The words made me feel grateful to her very much.
Years passed, but it was still a memory that I cannot forget in my life. Every time I think about it, I'm always feel ashamed and promising myself never to lie again.